Combined type-writing and computing machine.



HOYT. COMBlNED TYPE WRlTING AND COMPUUNG MACHINE.

APPLICATION FILED SEPT-27.19l3- RENEWED NOV. 3. @917.

- it m m? mm T. 2H 1H .3 vD es WEN E ow Di R. F. HOYT. COMBINED TYPE WRITING AND COMPUTING MACHINE APPLICATIONFILED SEPT.2?. 1913. RENEWED NOV- 3.1911.

1,256,309. Patented Feb. 12,1918.

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v ATTDR Y R. F. HOYT. COMBINED TYPE WRITING AND COMPUTING MACH'INE. APPLICATION FILED SEPT.27,19131 RENEWED NOV. 3.1917.

Patented Feb. 12, 1918. sHEETs-sHEET a.

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FEQQWWOM RICHARD F. I-IOYT, OF PHILADELP MENTS, TO UNDERRVCGEE CORPORATION OF NEV] YCRK.

A, EENNSYLVANXA, ASSIGNOR, BY MESNE ASSIGN- MA'GHINE CGI...

ANY, 0? NEVT YORK, N. Y., A

COMBINED TYPE-VVVEITITIG AND COMPUTING IVEACHINE.

Application filed September 27, 1918, Serial No. 782,076.

To all wit-0777, it may concern:

Beit known that I, RICHARD F. Hora", a citizen of the United States, residing in Olney, Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented certain new and useful Improvements in Combined Type-Writing and Com puting Machines, of which the rollowing is a specification.

My invention relates to computing machines, particularly combined typewriting and computing machines, and especially to means for indicating on the work-sheet certain conditions of the machine, etc.

In computing machines which both print and register numbers, it is advantageous to have some means for showing that the operative has done the work correctly, and for keeping track of the number of corrections which may have been made.

It is advantageous to show on the worksheet that the number wheels were standing at Zero when the computation was begun. This is especially advantageous in machines which both add and subtract. In such machines, if a total or answer is copied onto the written record of the numbers, such copying will bring the computing devices back to zero if an addition or subtraction key is properly set before such copying is be un.

The fact that the computing devices are thus returned to zero may be printed on the record by means of a special type, which indicates that the operative in copying such a total, has correctly copied the numbers shown in the computing devices.

Another point which it is advantageous to show, is whether an error was made at a given point and later corrected; for it is while correcting one error that a second error is especially likely to occur. I have found it advantageous to so connect the computing devices that when an error has been made and is being corrected, it is impossible to further operate the computing machine without printing such a sign, as for example, the letter E, to indicate that an error has been made and corrected.

My invention is disclosed as applied to an Underwood-Hanson combined typewriting and computing machine, such for instance as that shown in the British Patent No. 3390 of 1912, wherein the numbers written by the numeral keys of the typewriter are set up on pins forming a register, and the num- Specification of Letters Patent.

Patented Feb. 12, 1918.

Renewed November 3, 1917. Serial No. 200,036.

bcrs thus registered are later carried into the computing wheels forming part of a totalizer from which the desired answer is to be read. Such machines are usually provided with an error key for restoring the indexpins of any number that has been erroneously registered, and are also usually pro vided either with a key for returning the computing wheels to zero, or else with a key for printing a sign which will show that the computing wheels stand at zero.

In order to show that the wheels stand at zero, a special type-bar may be so connected that the depression of the zeroizing or Zeroproving key will cause the operation of said special type-bar. This operation of the type-bar may be caused by a spring, which is automatically released whenever such a zero key is depressed. The general operator, which serves to carry the numbers registered into the computing wheels, may automatically restore said special type-bar to its normal position, and re-tension its operating spring.

The usual error key of such machines may be also caused to operate a type-bar automatically whenever it is depressed, and said type-bar may advantageously be the same type-bar on which the zero type is mounted.

Preferably one of said keys prints a different sign from the other, and to bring this about, said type-bar carries two types which may be the usual upper and lower case type on a type-bar. The error key may cause the typew 'iter platen to be shifted so that the upper case type will write and print the letter E or other desired error sign.

The platen may be restored so that the type will write in the normal. lower case by the general operator which, as stated above, serves to ca my the numbers registered into the computing wheels.

Gther features and advantages will hereinafter appear.

In the accompanying drawings,

Figure l is a sectional side view of an Underwood-E ianson combined typewriting and computing machine showing my invention as applied thereto.

Fig. 2 is a side view looking in the opposite directi n, showing the error and Zero keys and some of their connections.

I 3 F1 3 1s a perspective view oi the parts shown in Fig. 2, together with some further connections.

Fig. 4: is a perspective view of the typehead for printing the error and zero signs.

Fig. 5 is a diagrammatic perspective View of the parts of the latch for operating the platen-shift.

Fig; 6 is a side view showing the connections at the moment the error key is depressed, but before the type-bar has risen to write on the platen.

Fig. 7 is a similar view taken a moment later when the error key is completing the operation of the various parts.

In the Underwood-Hanson combined typewriting and computing machine the usual alphabet and numeral keys 1 and depress key levers 3 to swing type-bars l upwardly and rearwardly against a platen 5, to cause lower case type 6 and upper case type T to write on the platen. Said platen is mounted in a carriage 8 which is fed along scm'atz'm in the usual manner (not shown herein) by heels 9 on the type-bars at each depression of the numeral keys.

The typewriting machine also includes the usual platen-shift key 10 on an elbow lever 11, said elbow lever, when the platen-shift key is depressed, swinging forwardly against one arm of a bell crank 12, to cause the other arm 13 thereof to swing upwardly and lift the platen 5 in the carriage 8 by means of a wheel 14 forming part of the platen-shift frame 15, said wheel riding on a rail 16 fast on the bell crank lever or arm 13.

Whenever the platen-shift key 10 is depressed, it raises the platen-shift frame until a stop 17 thereon strikes a stop 18 forming part of the typewriter carriage, in which position the upper case type 7, as seen in Fig. 7, will write on a worksheet passed around the platen 5.

As the typewriter carriage 8 travels along, a tappet 19 thereon passes under a series of jacks 20 pivoted at 21, so as to raise the forward ends thereof seriatim, depressing the rear ends so as to raise scriat'im into ef fective position a series of computation members or pin-bars 23 forming part of the computing mechanism proper. Whenever any one of said computation members 23 is raised to efl'ective position, its pins 2st stand within the range of action of pin-setting bars 25, said pin-setting bars being so connected to the numeral keys that whenever a numeral key is depressed, its corresponding pin-setting bar 25 will be simultaneously depressed and will set up, namely, depress the pin 24 on the computation member momentarily in efiective position.

The connections for bringing about the selection of the computation bars 23 include a series of rods 26, there being one rod for each jack 20, and each of said rods being in engagement at its lower end with a lever 27 pivoted at 28 between its ends, so that the forward end 29 of each lever will be raised when its jack 20 is moved by the tappet 19.

Since the typewriter carriage 8 travels to the left and the computing wheels are fixed relatively to the carriage, a transposition de vice 30 such as shown in the patent hereinloefore referred to is interposed between the lever :27 and the computation member 23 so that when the right-hand jack 20 is operated the left-hand computation member 23 is moved to effective position, with the result that when the highest or lefthand digit in any number is written, the left-hand compu tation meml er 23 is in effective position.

The pins on said computation member .23 are set by the numeral keys 2 through stems 31 of which there is one for each numeral key; and said. stems as they descend strike rock arms fast on rock shafts rock sh;- ts each being connected to its pin-setting bar which bar forms part of a lii'ikage operated by the shaft 33.

l i hcn a number has had all its digits set up on tl e pins 24- by the act of writing them with the numeral keys 2, said numbers are carried into computing or dial wheels 3-1 wherein the numbers are added. For so carrying the numbers into the computing wheels, there is provided general operator including cross-bar which travels forwardly, intercepting the lower end of any depressed pin 2st, and correspondingly curries forward thereby the computation member 23 so that a rack bar 36 forming the forward end of said computation member 23 turns its computing wheel. Set by a pinion 37 connected to its computing wheel.

Said general operator also includes si de-bars 38 on which are cut teeth 39 by which teeth the general operator may be driven, said teeth for this pu pose meshing with an idle pinion 4:0, said pinion being driven. by a handle ll fast to a segment 42 which meshes with the idle pinion L0. When the handle 11 is pulled forwardly, the general operator causes the computation members to carry the numbers registered therein into the com puting wheels 34-. On the return stroke of the handle ll, the carry-over devices 18 are operated seriatim in the usual manner by the drive shaft 68, and the computation members 23 are returned to their normal. position by a second cross-bar forming part of the general operator. The wheels 3 L are not rotated on the return stroke of the general operator owing to a pawl-and-ratchet connection between them and the pinions 37, said connection. not being shown herein.

At the very end of the return stroke of the general operator, the set pins 24 are restored to their normal ineffective position by means of a pin-restoring plate 50 which is lifted. by a catch (not shown herein but shown in Fig. 12 of said patent) momentarily to a height sufiicient to restore the set pins 24. Said pin-restoringplate 50 in restoring said ins, has a parallel motion given to it by the ell crank levers 51 which support it and are joined together by links 52.

Each of the computing wheels 34 is normally held alined so as to display its numerals through a sight opening 45 by a detent'46 pivoted below the wheels at 47, and normally held engaged with shallow teeth 48 on the computing wheels by a spring 49.

Before beginning to Write a number which is'to be registered in the computing wheels 84, it is desirable to print a sign showing that said wheels stand at zero when the cont putation is begun. 7 To so print a sign, the machine is provided with a star-printing key 53, and said key is provided with such connections that if it is operated when the computing wheels stand at zero, it will cause a special type to print a star on the worksheet on the platen; but at other times said star can not be printed.

To bring this result about, there is provideda special type-bar 54 provided with a type-head 55 comprising the type *f and the usual heel 9, which type-bar, whenever the star key 53 is operated, automatically rises to print on the platen 5. To cause such automatic printing, the type-bar 54 has a key lever 23 of the usual kind, which is cut off at 56, and by connections described hereinafter is normally under tension of a spring 57 which tends to swing-the type-bar 54 upwardly to print. Said spring, however, is normally prevented from operating by a holding catch 58;

The connections between the spring 57 and the key lever which is cut off at 56, include a link 59 (Fig. 3) extending downwardly from said key lever to a rock arm 60 fast on a rock shaft 61, said rock shaft also carrying a rock arm 62 to which the spring is connected. Thus said spring 57 would swing the rock shaft 61 to operate the typebar 54, if the rock arm 62 were not supported by a pendent link 63 pivoted on said rock arm and carrying at its lower end a lug 64 which normally rests on the catch 58 and is held up thereby.

Said catch 58 is swung to ineffective position whenever the star key 58 is operated, there-by causing the spring 57 to ogerate the type-bar 54. To thus swing the catch 58, the star key has its stem extended downwardly at 65 to rest on a rock arm 66 fast on a trans verse shaft 67 on the machine, and said shaft also has fast thereon the catch 58 so that a rocking of the shaft 67 by the star key 53 will swing the catch 58 clear of the lug 64 and operate the star type-bar 54.

When the star type-bar has thus been operated, the typebar is returned to normal position, and the spring 57 retensioned by the operation of the general operator. For

this purpose, the carry-over drive shaft 68 of the carry-over mechanism is employed, provided with the pinion 69 and the one-way clutch for driving it in one direction only during the return stroke of the carry-over mechanism. Said drive shaft 68 is provided with a cam 70, which cam during said return stroke carries its high end 71 under a lug or roller 72 fast on the rock arm 62 to which the spring 57 is fast, and lifts said rock arm against the tension of the spring 57, thus restoring the star type-bar 54 to normal posi tion, and drawing the link 63 up past the catch 58, so that said catch will he again effective to hold the lug 64. The lower side of the catch 58 is formed as a cam to swing the link 63 clear of it in its upward stroke.

To permit the link 63 to thus swing past the catch 58, said link is pivoted on the rock arm 62 at 7 3, and its lower end is normally swung forwardly to effective position by a spring 74. The lower end of said link 68 is extended at 75 so that said link will strike the shaft 67 and be prevented from swinging too far forwardly under the tension of the spring 74. The catch 58, it will be noted, is normally swung rearwardly under the lug 64 by a spring 76, which encircles the shaft 67 and holds the catch 58 against a pin 58.

If the computing wheels do not stand at zero, it is impossible to operate the star key 53, because unless said wheels stand at zero, one of the dctents 46 will be swung outwardly, seen at Fig. 1, to carry a bail 77 pivoted on the shaft 47 under a lug 78 fast on the star key stem. When said bail is thus swung outwardly, it looks the star key against operation. The. computing wheels 34 are provided with specially cut-away teeth 7 9 at such a point in their revolution that th detents 46 will sink etween said cutaway teeth deeply enough to allow the bail 77 to be swung forwardly by its spring 80. At the other points, the teeth 48 (which are identical with the teeth 79, except that they are not cut away quite so far) will hold the detents 46 far enough out to swing the bail 77 under the lug '78 of the star key stem.

Since the cut-away teeth 79 are so placed that they permit the detents 46 to enter them u hen the con'iputing wheels stand at zero, the bail 77 Will stand c195 of the tar key lug 78 when the computing wheels are at zero, and thus said star key 53 can operate the star-printing mechanism when the computing wheels are at zero.

The machine also includes the error key 81 which, according to my invention, is connected to print the letter E every time the error key is operated. The error key 81 includes connections to the pin-restoring plate 50 for restoring the set pins 24, said connections including a lever 105 pivoted between its ends at 166, the rear end thereof underlying one of the bell cranks 51 which carry the pin-restoring plate 50, while the other end is adapted to be snapped downwardly by depression of the error key 81. To bring about this depression, the pin-restoring lever 105 is connected to a. lug 107 on the error key by a spring 108 in such a way that depression of the error key tensions said spring, but the tension must be considerable before the error key will be released to be effective on the pin-restoring plate 50.

in order to definitely obtain the necessary snap of the lever 105, the forward end of the lever is first prevented from descending withthe error key, being arrested by a bell crank arm 109 which normally is held nearly erect under a lug 110 on the pinrestoring lever 105 by means of a spring 111. i l 'hen, however, the error key has been depressed considerably, the pin 112 on said key to which the spring 108 is anchored, strikes an arm 113 of the bell crank arm 109 and carries the bell crank arm 109 clear of the lever lug 110, thus permitting the lever 105 to be snapped downwardly by the spring 108. The lever 105 is guided at the front in a slot 11 1 in a plate 115 forming part of the computing machine.

To print the letter E, said key is con nected to first shift the platen and later, but on the same operation, to operate the star type-bar 5% of which the typehead co1nprises in its upper case the letter E. To do this, the stem 82 of said key 81 operates a rock arm 88 similar to the rock arm 68 and like it fast to the rock shaft 67, so that depressing said error key, if no other operation took place in the meantime, would cause the printing of a star. Said error key, however, is provided near the top of its stem with a lug 81 which will cause the platen to be shifted to upper case position just before tne star type-bar 5 1 is effective to print.

To shift the platen at the depression of the error key, the usual platen-shift key 10 has encircling its lever 85 a pendent link 86 which a spring 87 normally tends to draw down, so as to raise the platen. Said link is provided at its upper end with a slot 88 in which the platen-shift key 10 can be operated idly in the usual manner; said link being held in proper position along the key lever 85 by pins 89 on said key lever.

The link 86 is normally restrained from shifting the platen by a catch 90 which normally lies under the flat side of a notch 91 cut at the lower end of the link 88. lVhenever the error key 81 is depressed, said catch is released to permit the spring 87 to draw down the shift key 10 and shift the platen to upper case printing position. For this purpose, the lug 81 of the stem of the error key 81, as said key descends, almost immediately strikes a rock arm 9:2 fast on a rock shaft 93 extending to one side of the 1,2ss,soe

computing mechanism; said rock shaft also carrying a second rock arm 91, said lastnamed arm being connected to the catch 90 by a link 95 in such a way that every time the error key 81 is depressed, the catch 90 will be moved forwardly clear of the link 86, and thus permit the spring 87 to shift the platen.

To guide the catch 90 as it slides rearwardly under the depression of the error key 81, it is provided with a slot 96 within which ride two headed pins 97 fast on a bracket 98 riveted by pins 100 to the frame of the computing machine. The catch 90 is normally held in its forward position where it supports the link 86 by a spring 99 anchored i an extension of one of the pins 100 which fastens the bracket 98 to the frame of the machine.

In order to prevent the catch 90 from dragging the link 86 rearwardly whenever the error key is depressed, the bracket is provided with downward extensions 101 forming guides which lie on each side of an extension of the link 86, and thus prevent the flat side of the notch 91 from catching on the bracket itself.

The platen is restored to the normal lower case printing position through the medium of the general operator which positively lifts the link 86 against the tension of the spring 87, freeing the shift key 10. For this purpose, the general operator is provided with a cam plate 102 fast on the side-bar 38 adjacent the case-shift link 86, and the inclined extension 103 of said cam plate on the forward movement of the general operator rises under a stud or roller 101 fast on the link 86, so as to raise said link to such a height that the catch 90 will catch in the notch 91, thus freeing the shift key 10.

Though the machine has been described as an adding machine, it may also be used to subtract as is disclosed in the copending case of Hans Hanson, Serial No. 616.550, filed May 11, 1911, and British Patent No. 10,902 of 1912, by the operation of a subtraction key, said key altering some of the connections. lVhen such a subtraction key is depressed and a total shown in the wheels 3% is copied onto the worksheet on the platen 5, the act of writing such a total will register the total subtractively on the computation members 28. T he actuation of the general operator will then bring the wheels 31- to Zero. The star key 53 may then he operated to print a star. This star will prove to any reader of the work-sheet that the total was correctly copied from the sum of the items displayed on the wheels 81-. If, however, said total was incorrectly copied and later corrected by operating the error key 81 to erase the number registered on the computation members 28, the fact that this was done will be shown by an E printed opposite said total by the error key 81.

I do not claim anything disclosed in. the co-pending application of Fred Walsleben, Serial No. 802,208, filed November 21, 19123, for combined typewriting and computing machines.

Variations may be resorted to within the scope of the invention, and no ions ot the improvements may be use-1i v-ritncut others.

Having thus described my invention, I claim:

1. In a combined typewi puting machine, the can ition with nu- Ineral keys and a spe 'al connected with the computing mechanism, and controlling the latter, of a case-s mechanism, a connection between said special key and said case-shift mechanism for controlling the operation thereof, and a printing type also controlled by said special. to be brought into use at the operation oi said cascshiit mechanism.

2. In a combined. t pewriting and computing machine, the combina ion with a case-shift mechanism, oi. two noa-computi keys connected *ith the co rpnting mecl nism, a single type-ea ner controlled said keys, and a conne n between one of said keys and said case-shift.

3. In a recording and registering computing machine, the combination with a single type-carrier, of two non-computing keys therefor connected with the cmnputing ing and. com

key

mechanism, a character on said car ier for each key, and a connection between said.

keys and said. type-carrier for selectively printing either character irom a key.

4. In a combined type puting machine, the our moral keys and a case-sl I, mechai computation membe s in which numb temporarily register wheels, a general operator for c .umbers so registered into said whee a lieconnected to the computing mecl anisin controlling the shifting of the case, and a member connected to the general operator for controlling the restoration of the case to its normal. position.

5. In a combined typewriting and computing machine, the combination with computing wheels and a key operable only when said wheels stand at zero. t a type connected to said key, a case-shirt mechanism for the typewriter, an error ke tor the coinputing mechanism, a connection from said error key to said type, and a connection trom said error key to said caseshift.

6. In a combined typewriting and soon puting machine, the combination with an error key and a clearance k y, o1"- a typelmr operated by both of said keys, a case-shift mechanismcontl'olled byone (it said keys,

numeral keys, a register in which numbers are set up by said numeral keys, dial wheels into which said numbers are later carried. a general operator tor so carrying the registered numbers, and resilient means tensioned by said general operator for furnishing the power for thus operating the typwbar and case shiit.

7. In a combined ty ew1.iting and com puting machine, the combination with a case-shift mechanism, computing wheels and numeral keys, of a device in which numbers are temporarily registered by said ke a general operator for carrying the numli crs thus registered into said wheels, a special non-computing key connected with the computing mechanism, a special type-bar con nected to said special key. a spring for shifting the case, a catch-under the control of said special key for releasing said spring to operate said case-shift, and a member on the general operator for re-tensioning said spring to put it again under the control oi said special key.

8. In a combined typewriting and computing machine, the combination with printing types, numeral keys and computing mechanism, of a case-shift mechanism to cause said types to print difl'erent characters, a special key connected with the computing mechanism, means operable by said key to cause one of said types to print, and devices also operable by said special key to control said case-shift.

9. In a combined typewriting and computing' machine, the combination with a :ase-shift mechanism and numeral keys, of printing, types, a key for shifting the case, another key eiiective on the computing mechanism, a link for shifting said case independently of the shift key, and a connection from said other key for automatically operating said link.

10. In a combined typewriting and com puting lllflwlllltt, the combination with a case-shittmechanism, a device in which numbers are temporarily registered, numeral keys and computing wheels, of a general operator for carrying the numbers registered into the wheels, and a case-shifting and restoring mechanism including means under the control of the general operator tor controlling the restoration of the caseshift mechanism.

11. In a combined typewriting and com puting machine, the combination with computing wheels and printing types, of numeral keys, two non-numeralkeys associated with the computing mechanism, a single printing type-head under the control of both of said keys and having a plurality of characters thereon, a lock under the joint control of said wheels for holding one of said -non-numeral keys against operation until all of said wheels reach a certain position, which position is indicated upon the sheet by the printing of one character by said key, and a case-shift mechanism under the control of the other non-numeral key to enable another of said characters to print.

12. In a combined typewriting and cont pnting machine, the combination with numeral keys and computing wheels, of printing types, means causing the types to print at the actuation of the keys, an error key, indexing devices, means controlled by said error key for restoring set indexing devices to normal positions, a special type, and means under the control of the error key to cause said special type to be printed antomatically opposite the number printed on the work-sheet, to indicate that such number was not run up in the computation.

13. The combination with keys, a double case type operated by said keys, and having thereon a plurality of faces for printing special indicating signs, and a case-shift mechanism, of a shift key to operate said case-shift mechanism to enable said type to print. a key for writing one of said signs, a special key for automatically shifting said case-shift mechanism and writing the other sign, a computing mechanism, and means to enable said special key to control said computing mechanism.

14;. The combination with keys. double case type operated by said keys, and a caseshift mechanism, of a shift key to shift said case-shift mechanism to enable said type to print. a type-bar, a key for writing by said type-bar in one case, a spring for operating said type-bar, a special key for writing by said type-bar. a spring for shifting said case-shift mechanism when said type-bar is operated by sa d special key, a computing mechanism. and m ans to enable said special key to control said computing mechanism.

15. In a combined typewriting and computing machine. the combination with computing mechanism, of a key connected with said computing mechanism, a second key also connected with the com uting mechanism. a type device controllable by either of said keys for printing on the work-sheet the characters corresponding therewith respectively, and a case-sh ft mechanism controllable by one of said keys.

16. In a combined typewriting and computing machine, the combination with computing mechanism, ot a key connected with said computing mechanism, a second key also connected with the computing mechanism, a type device controllable by either of said keys for printing on the work-sheet the characters corresponding therewith respectively. a case-shift mechanism. a spring for operating said case-shift mechanism, a. latch releasable by one of said keys for restraining the operation of said case-shitt mechanism by said spring, a general operator for the computing mechanism. and means connected to said general operator for restoring the case-shift mechanism and retensioning said spring.

17. In a combined typewriting and compnting machine, the combination of a printing type, a spring to operate the same to print, a latch to restrain said printing type from being operated by said spring, a plurality of independently operable conditioncontrolling keys for said computing machine, and means to enable either of said keys to release said latch. and cause said printing type to print a different character from that which it prints at the operation of the other key.

18. In a combined typewriting and computing machine, the combination of a printing type, having a plurality of characters. a spring to operate the same to print, a latch to restrain said printing type from being operated by said spring, a plurality of independently operable condition -controlling keys for said computing machine. means to enable either of said keys to release said latch, and case-shifting means controlled by one of said keys for enabling said printing type to print a different character from that printed under the control of the other of said keys.

19. The combination with a computing mechanism, of a type, a spring normally tendin to drive said type. a latch restraining said type, a rock shaft for releasing said latch. a plurality of arms on said rock shaft, a plurality of independently operable keys to operate said rock shaft by means of said arms, and means under the control of said keys for putting the computing mechanism in ditlcrent conditions.

20. The combination with a computing mechanism, of a type, a spring normally tending to drive said type. a latch restraining said type, a rock shaft for releasing said latch, a plurality oi independently operable keys to operate said rock shaft, means under the control of said keys tor putting the computing mechanism in different conditions, a general operator. and means under the control of said general operator for re storing said type and retensioning said spring.

21. The combination with a computing mechanism, of a type, a spring normally tending to drive said type, a latch restraining said type, a rock shaft for releasing said latch, a plurality of independently operable keys to operate said rock shaft. means under the control of said keys for putting the computing mechanism in different conditions, a general operator, means under the control of said general operator for restoring said type and retensioning said spring, a caseshift mechanism, a spring to operate said case-shift mechanism, a latch for restraining said case-shift mechanism, means operated by one of said keys for releasing said case-shift latch, and means connected to said general operator for restoring said case shift mechanism and retensioning its spring.

22. In a computing machine having the usual computing devices, indexing devices settable to control the computing devices, and an error key for rendering ineffective any set indexing device; the combination With a printing member and means dependent upon actuation of said error key to control said member, to print on the Work-sheet to denote that said settable means has been rendered ineffective.

23. In a combined typewriting and computing machine having computing Wheels and a case-shiftmechanism; the combination of a key operable only when said wheels stand at zero, an error key, and a type controlled by either of said keys to print, one

of said keys also controlling the case-shift Copies of this patent may be obtained for five cents each, by addressing the ommissioner of Patents,

Washington, I). G." 

